Apparatus and method of constructing and sinking alpha caisson



Ma 31 1927. r y 7 J. R. FREEMAN APPARATUS AND METHOD OF CONSTRUCTING'AND SINKING A CAISSON 6 Sheets-Sheet 1 2 no 4- {lily r Y lnvenfon John FLFveemcm May 31, 1927. 1,630,337

J. R. FREEMAN APPARATUS AND METHOD OF CONSTRUCTING AND SINKING A CAISSON Filed Aug. 24, 1921 e Sheets-Sheet 2 0 I n I Q I no 0 a In x r. 0 K

dohn R. Fireemqn byMMkW 4 Anys.

May 31 1927. 1,630,337

J. R. FREEMAN APPARATUS AND METHOD OF CONSTRUGTING AND SINKING A CAISSON Filed Aug. 24,qI L921 6 fibeets-Sheet 3 lnvenTor.. John R. Freeman byMWJM Aflys.

Ma 31 1927. y J. R. FREEMAN APPARATUS AND METHOD OF CONSTRUQTING AND SINKING A CAISSON Filed Aug/24. 192i 6 Sheets-Sheet 4 \nvenTo dohn RFreemun byW I 1,630,337 y 1927' J. R. FREEMAN:

APPARATUS AND METHOD OF CONSTRUCTING AND SINKING A CAISSON Filed Aug. 24. 1921 6 Sheets-Sheet 5 Fig.6. I 30 I lnvenTor.

' John R. Freeman AITys.

' 1,630 337 May J. R. FREEMAN APPARATUS AND METHOD OF CONSTRUCTING AND SINKING A CAISSON Filed Aug. 24. 1921 s Sheets-Sheet 6 \nvenTor.

John R. Freeman 'B MMQW I Anys.

sinks.

Patented May 31, 1927.

UNHTE s'r a'rrzs re ns,-

Parser JOHN R. rnnnMAn, or PROVIDENCE; RHODE IsLAnn,

7 Application filed August 24, 1921. SeriaLNQ. 494,944.

This invention relates to an apparatus and method for constructing and sinking a caisson such as a hollow concrete supporting pier for a bridge or other purpose. The in vention is particularly designed for. use in connection with the construction and sinking of such a caisson or pier in silt orso'ft earth such as a river bottom but/maybe employed under any conditions where it is found advantageous.

One object of the invention is to provide an apparatus reacting against a loaded support surrounding the caisson for producing a downward thrust on the caisson periphery to assist in sinking it into the earth, thus expediting the work and assisting in the dredging action.

Another object of the invention is to provide an apparatus employing extensible suspending connections extending from a support surrounding the caisson to points on the periphery of the caisson and controlling the extension of these connections to insure a gradual and even sinking of the caisson into the earth, thus preventing any sudden drop of the caisson due to irregular conditions in the earth through which it is sunk and insure the gradual and even sinking of the caisson.

- Another object of the invention is to provide means on the support surrounding the caisson and engaging the caisson periphery for centering and guiding the caisson as it Another object of the invention is, to conibine two'or more of the 'foregoingfeatures in the apparatus so as to insure under the 'pre-' vailing conditions the gradual, even and ver- I tical sinking of the caisson.

These and other objectsand features of the invention will appear. more fully from the accompanying description and drawings and will be particularly pointed outinithe J 5 "the, bed of the rivei and filling'thespace claims. g

The drawings represent simple and preferred forms of apparatus for carrying out the main feature of the invention in connection with the construction and sinking of a hollow concrete-supporting pier designed tor support a bridge from the bed of a river.

The construction illustrated is particularly designed for use in comparatively soft-earth such as alluvial soil orsilt often forming to a great depth the bed of a river at its delta.

, In thedrawingsz' Fig. 1 is asoniewhat diagrammatic view chiefly in vertical crosssection taken transversely of the river bed, showing the pier sunkand one form of structure surround; in the pier and eniployed in sinking the pier.

Fig. 2 is a top plan view partially horizontal cross section, showing a section'of the surrounding structure and a caisson being sunk. v

Fig. 3 is a view chiefly in vertical cross section showing a section of the pier being section of the sunk and surrounding structure and one of pier and a portion of a reinforcing column 1 and some of the other reinforcements of the pierl v a Fig. 8 is a front elevation of a portion of the construction shown in Fig, 7

Fig. 9 is a view in perspective of a portion of one of the columns of the pier.

In the 1 embodiment of the inventionherein illustrated where the pier isto be sunk in ,the bed of a river, a suitable cofieredam'and support or curb, surrounding the spot at whichthe pier is'to be sunk, are "firstyco'n- Qst-ructed. The coder-dam is constructed'at a suitable distance around the pier site and I to a height above the water level. In theform illustrated this cotter-dam is formed, by driving piles 1 in-concentric, rows into between, the rows. of piles with Chinese bundles of kaoliang 2, but any usual and gradually covered withajdike 3 ofear'th, the earth removed in the dredging operation -rduring[the sinking :of the pier. being utilized for that; purpose. -,Stone' rip rap t, may be employed where necessary to support and protect the cotter-dam and the dike as,

' forexample, on the upstream side. Immea surround ng the di ately a d aces.

ably a heavy timber framework construction supported on and tied into the be'd of the river by the sheetpiling 5 and by suitable piles 6 driven into the bed of the river. In

the form illustrated thiscurb or support comprises the lowerradially extending beams Tsecured to beams 8 carried by the sheetpiling,and beams 9, carried by or supported on the piles 6. .A suitable trussed framework is built up from the beam 7 and includes the vertical beams 10 adjacent the pier and the vertical beams 11 in a surrounding row. These beams carry the upper row of radial transverse beams 12 tied together by the beams 13 at the front and 14 at the rear and braced transversely by the braces 15." The entire framework is firmly bolted v together.

A suitable working platform 16 is pro-.

vided on the beams 12 and surrounds the pier site,

A'suitable trestle, formed by trusses 17 carried on the piles and other piles 18 and the curb already described, is constructed in 1 any suitable manner and provides a trackway or platform 19' upon which the materials employedinthe construction andsinkingof the pier may be brought, stored' 'and handled. Thisplatform 19 may beextended entirely about the pier and be of such size and construction. as isrequired under the particular conditions.

The pier' is shown as constructed of rein.-

e'rations in' a} familiar-manner; The lower edge of the hollow pier. or. caisson is beveled interior-1y to provide a cutting edge at the exterior and the lowersectionof the pier is rigidly reinforced and provided with a steel cutting shoe which remains as apermanent portion of the pier. The pier isshown as of generally circular or polygonal. cross section throughout that portion embedded in the earth. The portion of the pierfabove the earth, in the form illustrated, is tapered inwardly at 20 at the sides'so as to present supporting section 21 extending length- Y wiseor up andidown stream the usual removed when' the first section is ready for sinking.

"After the cotter-dam andtimhericurb, or-

supporting structure have been erected, the "first or lowermost section of the pier or caisson is constructed upon'and rests upon a temporary plank foundation' 22, which is A steel shoe 23, forming the cutting edge, 7

is bolted to a series of metal frames, shown in detail 111 Fig. 7. These frames each comprise the vertical angle-irons 241 and the 1nclined angle-irons 25 secured together 'by the transverse plates 26. These frames are arranged radially and faced at the lower exterior with a metal plate 27 and the lower interior with metal plates 28 and 29, the

cutting steel shoe 23 being bolted between. the plates 27 and 29. These frames form a strong reinforcement for the lower portion of the pierand also provide the forms for the concrete at the very lowermost section. The angle-irons 2 1- at their upper ends are bolted to the flanges or rigid vertical columns 30, which preferably extend throughout thelength of the pier and serve as'vertical reinforcementsfor the pier and to receive and transmit the forces of thrust and draft employed in connection with thesinking of the pier.

The forms employed in constructing the pier may be of any suitable construction. As illustrated, the interior inclined surface above the plate 28 is completed by a wooden form 31. Otherwise the forms for the interior and exterior comprise suitable sectional metal plates 32, between whichthe concrete is poured, and which are removed after the concrete is set and before sinking.

Suitable additional reinforcements may be provided as required for the concrete. Preferably, metal rods 33 are arranged concentrically in the lower beveled section and held in place by resting on the plates 26. u

These give a very strong reinforcement to this section of the pier. Preferably also,

7 I the entire length ofthe pier is reinforced forced concrete poured in successive layers 11 above the ground and just prior to sinking. The earth is removed from the inside of the pier by suitable dredging or pumping op placeafter the "pier is sunk to itsresting tical' columns 30 employed will vary with thesize of the pier, but in the construction illustrated 16' are provided.

v The columns 30, which are thus built-into: i i the concrete of the pier as his formed, are

an lmportantffeature.2', They are shown as of the channel typeof iron beam having the:

outwardly projecting flanges 37 and 38' and lowermost the back 39.. V The brackets or angle-irons i 35, already referred-to, arebolted ito the back 39 and' thus' extend inwardly-and are. embedded in the. concrete. The space be tween the flanges 37 and 88 is filled with concrete as these beams sink with the pier into the earth.

An important feature of the invention relates to the means and method employed for the forcing of the pier or caisson into the earth and the control of its sinking movement. The invention especially enables the pier to be constructed and-sunk with great speed because the operations of dredging, sinking, form shifting and consinking force.

icrete pouring can go on simultaneously.

Heretofore it has been customary to load the caisson with heavy weights piled upon it or else to make the caisson itself excessively heavy in order to secure the necessary Under these conditions 1 the grab bucket of the dredger often removes the earth far below the cutting edge and then the caisson drops suddenly, not infrequently breaking or nuurmg the caisson or the surrounding working structure and intions. Thisfis an important feature because lit) 7 means may be provided uponithe vertical,

juring those employed. This irregular sinking movement of the caisson also permits the mud or soft earth to flow into the interior of the caisson, delaying the work and requiring an undue amount of pumping.

The present invention secures the steady,

particular construction of the jacks is not and even sinking of the caisson into the earth as the earth is dredged out or removed from the interior. There 18 thus no sudden drop or movement of the caisson and little danger of a sudden mflow of mud or soft earth; Furthermore, the movement of the caisson is maintained evenly throughby which the invention secures these re-.

sults is illustrated and embodies two main features. jacks engaging against the caisson peripheryand engaging and reacting upwardly against the surrounding support; and second, a plurality medium ofthe vertical columns, so that'the force, whether of thrust or draft, is transmit-ted through these columns to the .comparatively hard set cement of thelower secit prevents the caisson or pier from being cracked 'or broken apart as 1t descends,

either underits own weightorunder the thrusting forces, into the ground. Suitable columns at frequent vertical intervals to vbe engaged by the jacks and extensible suspending connections. In the form illustraterted by each jack may be varied as the First, a plurality of expansible and acting downwardly ed a plurality of steps are provided at verticalintervals upon each vertical column. These are shown'as heavyirion brackets securely bolted in place within the channel section of the vertical columns The back portion 40 of each bracket is bolted to the back plate '39 of the column and the side flanges 41 are boltedrespectively to the side flanges 3'7- and' '38 of the column. Each bracket presents a horizontal projection or step 42 adapted onrits top face to receive the end of the ack and on its lower face'to' be caught'by a link or cross bar of the suspending connection. Preferably both of these devices will not act on the same step at the-same time, but if both are'used at the same time, the jack will engage one step and the suspending connection another step on the same column. a

The ja k m y be f any suitable are .conditions require. In the particularcom struction illustrated provision is made for sixteen powerful hydraulic jacks. As the involved in this invention, it is sufficient to illustrate them only. in a general way. 'lhe jack comprises a hydraulic cylinder 43 and a piston or thrust bar 44. At its upper end the jack abuts against a heavy cast; ing 45, fitting over the inner end of one of the beams '12. Thejack issupported by a frame 146, pivoted to the endo'f the-beam, and is counterbalanced by a weight, wh-ich' may be a tank 47 filled with sand, and connected bya rope. or cable 48, running over a pulley 49 with the jack. 'The" curb or framework surrounding the caisson is suitably .trussed or braced against the thrust of l the jack. For this purpose tension rods 50 and 51 with suitableturn 'buckles52 are of extensible suspending connections conshownconnecting the casting 45 to different 'nected to the caisson periphery and to the points on the lower beam of thecurbor framework. VV hen these jacks areuscd, the necessaryweight against, which the jack re; acts is secured by loading the curb or frame I work; This maybe done by buildinga plat be built higher by means of additional beams 55, a platform 56 may be builtonthe beams 12, a retaining wall 57 may: be

built at, the front'andthe load, of earth or .wet sand carried up onto the platform 56.

A tremendous pressure, sufficient-to over-f skin' friction, may be furnished byithe 'use come the resistance to sinking'including the vided for each chain, enabling it to be paid men employed.

' V (are provided, 20

suitable manner, as by hand.

drop j or irregular tilting;

out the caisson periphery. The jacks may not be needed save during the latter portion of the sinking of the caissonor save upon meeting with some dense ,or particularly resistant character of earth, but they afford -means by which under a wide variety of conditions the sinking of the caisson may be continued steadily andevenly, and they enable the caisson to be sunk as the dredging at the interior progresses, so that there is no danger the dredging proceeds and then the caisson falling with a jump and beingbroken or injuring the surrounding structure or the tended gradhlly under'sure control. In the form illustrated a worm screw winch is proout or extended an inch or two at atime andas. slowly as desired. "The chain 58 is shown as extended about the barrel 61 of the winch, carrying the worrnwheel 62. This worm wheel engages a worm 63 on a vertical shaft G l, which maybe turned in any The winch is firmly seated on the curb or surrounding framework and each, winch isshown asseated on the inner ends of'thebeams 12.

These suspending connections are very desir-able at the beginning of the sinking of theicaisson. They act to maintain itin vertical position as it starts to sinkandenab1e the sinking of the caisson to be controlled so that there isno danger of 'any sudden The 'suspending connections maybe employed "during any 7 soft quick iortionol the .sinking of the caisson or dur- 'ig'tlie entire operation, if desired. If the caisson in its, sinking penetrates apocket of fl or other similar. material, these .conne ions hold or sudc lenginjury to the surrounding struc- .It LliQ or to the men employed;

empl yed ing connections,

I The suspending connections may also be g .ally the jacks expand to. insure the evenfand steady movement of the caisson. By theuseof these two devices, that s,1the expanding acks and the extensible suspend- O ot'the caisson is prevented. j

7 The "caisson,-is

preferably centered and of the 'caissonholding back while ward taper.

These chains 58 are each it against droppingagainst' the with the jacks being paid, out

great rapidity of operation is secured under allconditions and all danher due to rregular orsudden movement" guided: in its movement by means provided on the curb or surrounding framework.

For this purpose suitable guide blocks 65 are placed on the vertical beams and suitable guide blocks 66 are secured to the inner ends of th 70' beam 7. Thecontacting faces oi these blocks are greased 1n the same manner as the launching ways are greased for r a ship. Thus, the caisson is centered and guided just prior to its entrance into the earth. r

Preferably also, means are provided for reducing the skin friction at the exterior of the caisson. Forrthis purpose two fea tures are provided. First, the exterionof the caisson is formed witha very small up- I This taper is barely large enough tov relieve the pressure of the surrounding earth and to admit the circulation of a thin lilm of waterwhile sinking and is not made sufficiently large enough to invite any extensive inward movement of the earthin which it is to be sunk. A taper of one per centwhere the river bed is'of silt or other similar formation,is found to be about s'uliicientQSecond, means are provided supplyinga thin film of. water adjacent the cutting "edge for lubrication.

For this purpose afplurality' of pipes 67 are built into the caisson as it is poured and extend up vertically to the top. At

their outer sides these pipes are bent horizontally around the caisson at a point a short distance above the cutting edge; and at their lower ends are provided wlth a plu ralitycf openings 68 through which small jets of water are forced at the exterior periphery of the caisson. These plpes are left in tlie'caiss'onand form an additional permanent vertical reinforcement.

In the construction illustrated when the caisson, here shown in the form ofa P1613,

is sunk to the desired depth, the bottom is closed by a'permanent plug of concrete 69,

poured in place by a'tremie or bucket Open ing at the bottom. "Theconcrete of this plug extends into and interlockswith the recesses "provided by the projections on the lower forms in the main walls of the caisson. This plug is also preferably braced with horizontal reinforcing bars 70 abutting interior periphery of the caisson walls." 7

The principles of construction involved.

inthe pier as an article of manufacture are,

however, made'the subjectimatter ofanother application.

ters Patent, 1si

1. in apparatus for sinking" a caisson; vertically comprising a support on the-earthf' surrounding the caisson, a plurality of eX-,

'pansibl'e jacks engaging and actingdown wardly aga nstthe. ca1sson-per1phery and l-laviiig thusdescribed myinvention, what l Clflllll as new, and desire to secure by Let-- 1 engaging and reacting upwardly against.

port to take up the reaction of the jacks,'

means for expanding the jacks gradually to force the caisson into the earth, and means carriedby the support and engaging the caisson periphery for centering and guiding the caisson in its descent.

2. An apparatus for sinking a caisson vertically comprising a support on the earth surrounding the caisson, a plurality of extensible suspending connections connected to the caisson periphery and to the'support, and means for gradually extending said connections to insure the gradual descent of the caisson throughout its periphery.

3. An apparatus for sinking a caisson vertically comprising the elements defined in claim 2 together with means carried by the support and engaging the caisson peripl1- cry for centering and guiding the caisson in its descent.

4. An apparatus for sinking a caisson vertically comprising a support on the earth surrounding the caisson, a plurality of expansible jacks engaging and acting downwardly against the caisson periphery and engaging and reacting upwardly against the support, a load on the support of sufficient weight together with that of the support to take up the reaction of the jacks, a plurality of extensible suspending connections connected to the caisson periphery and the support, means for gradually expanding said jacks, and means for gradually extending said connections, thus gradually to force the caisson into the earth and insure its even descent throughout its periphery.

5. An apparatus for sinking a caisson vertically comprising the elements defined in claim 4 together with means carried by the support and engaging the caisson periphery for centering and guiding the caisson in its descent.

6. An apparatus for sinking a caisson vertically comprising a support on the earth surrounding the caisson, and means carried by the support and engaging the caisson periphery for centering and guiding the caisson in its descent.

7. An apparatus for sinking a concrete caisson vertically comprising a plurality of rigid vertical columns built into the caisson.

periphery during its formation and vertically reinforcing and uniting the caisson, steps at vertical intervals on said columns, a support on the earth surrounding the caisson, a plurality of expansible jacks engaging and acting downwardly against said steps and engaging and reacting upwardly against the support, a load on the support of sufficient weight together with that of the support to take up the reaction of the jacks, and

means for gradually expanding the jacks,

its periphery.

whereby the caisson is gradually and evenly forced into the earth and the thrust of the jacks is transmitted through the vertical columns to the lower hard set concrete of the caisson.

8. An apparatus for sinking a concrete caisson vertlcally comprlslng a plural ty of rigid vertical columns built into the caisson periphery during its formation and verti cally reinforcing and uniting the caisson, steps at vertical intervals on said columns, a support on the earth surrounding the caisson, a plurality of extensible suspending connections connected to the steps and to the support, and means for gradually extending said connections to insure the gradual and even descent of the caisson throughout its periphery, the vertical columns acting to transmit the draft of the, extensible connections to the lower hard set concrete of the caisson. I

9. An apparatus for sinking a concrete caisson vertically comprising a. plurality of rigid vertical columns built into the caisson.

periphery during its formation and verti cally reinforcmg and unltlng the caisson,

steps at vertical intervals on said columns, a

support on the earth surrounding .the caisson, a plurality of expanslble 1acks engaging and acting downwardly against said steps and engaging and reacting upwardly against the support, a load on the support of sufficient weight together with that of the sup port to take up the reaction of the jacks, a plurality of extensible suspending connections connected to the steps and to the'support, and means for gradually. expanding the jacks, and means for gradually extending the connections to insure the'gradual andeven descent of the caisson throughout 10. The method of constructing-and sinking a concrete caisson which consists in pouring successively horizontal sections of the caisson, building into the caisson as the-sections are poured a plurality of rigid vertical columns, dredging the interior of the caisson, and applying a vertical downward thrust to said columns and therethrough past the relatively soft and fresh concrete to the lower section ofhard set concrete. I

11. The method of constructing andsinking a concrete caisson which consists in pour:

mg successively horizontal sections ofthe caisson, building into the caisson asthe sections are poured a plurality of rigid vertical columns, dredging the interior of the caisson, and applying a suspending draft to said columns and 'therethrough pastthe relatively soft and fresh concrete to the lower section of hard set concrete. I

In testimony whereof, I have signed m name to this specification.

JOHN R. FREEMAN. 

